Wireless networking has emerged as an inexpensive technology for connecting multiple users with other users within a wireless coverage area of a network as well as providing connections to other external networks, such as the World Wide Web. An exemplary wireless network may be a wireless local area network (“WLAN”) for providing radio communication between several devices using at least one wireless protocol. A wireless local area network may use radio frequency (“RF”) communication channels to communicate between multiple mobile units (“MUs”) and multiple stationary access points. The access points or access ports (both may be referred to herein as “APs”) of the WLAN may be positioned in various locations of the environment to prevent any coverage gaps in the wireless coverage.
A WLAN is a flexible data communications system that may either replace or extend a conventional, wired network. The WLAN may provide added functionality and mobility over a distributed environment. That is, the wired LAN transmits data from a first computing device to a further computing device across cables or wires that provide a link to the network and any devices connected thereto. The WLAN, however, relies upon radio waves to transfer data between wireless devices. Data is superimposed onto the radio wave through a process called modulation, whereby a carrier wave acts as a transmission medium.
Exchange of data between the wireless devices over the WLAN has been defined and regulated by standards ratified by the Institute of Electrical and Electronics Engineering (IEEE). These standards include a communication protocol generally known as 802.11, and having several versions, including 802.11a, 802.11b (“Wi-Fi”), 802.11e, 802.11g, 802.11n, and 802.11r. Recently, there has been a surge in deployment of 802.11-based wireless infrastructure networks to provide WLAN data sharing and wireless Internet access services in public places (e.g., “hot spots”).
In any wireless communications network, the term “roaming” may be used to describe the extension of service to an MU in motion from one AP coverage area to another AP coverage area. When a wireless user roams within a covered region during a call session, a network switch (or other network component) may transfer, or handoff, the MU between APs. A handoff may occur if the MU moves out of range of a current AP and can receive a stronger signal from a neighboring AP. In addition, a handoff may occur if the current AP has reached a servicing capacity and the neighboring AP is available for service. However, as an MU is handed-off from one AP to the next, portions of the “digitized” voice data may be lost during the transition.